PORTLAND, Maine — A group of doctors, sportsmen, scientists and parents led by the American Lung Association gathered Monday to urge Maine’s senators to support clean air legislation.

The coalition called on Sens. Susan Collins and Olympia Snowe to back tougher federal rules on mercury and air pollution from power plants and oppose efforts to delay stricter emissions standards for industrial boilers.

At a press conference, Mark Conley of Raymond said he sometimes has to keep his asthmatic son, Jake, indoors because air pollution compromises the 12-year-old’s breathing.

“Do we want our kids walking around in the future with masks on?” Conley said.

Story continues below advertisement.

The Environmental Protection Agency is expected this week to unveil first-ever national standards for mercury and other toxic pollutants released from power plant smokestacks. The agency says the standards will keep 91 percent of the mercury in coal from entering the air, preventing an estimated 11,000 heart attacks and 120,000 asthma attacks annually by 2016.

“While many parts of the country rely on coal power, the health effects from this relatively inexpensive resource are borne by the people of Maine,” Snowe said in a statement. “It is unacceptable that these costs are simply transferred from one region to another and that is why I have long supported reducing mercury pollution with cost-effective technologies.”

Art Cerullo, a member of the American Lung Association of Maine board, said at the press conference that Maine’s senators hold the key to preventing out-of-state polluters from dirtying Maine’s air. Behind him, an actor dressed as Santa placed gift boxes labeled “healthy air” and “healthy kids” into a stocking while a man dressed as the Grinch replaced them with chunks of coal.

“But it’s not just about health,” Cerullo said. “It’s about our ability to create jobs and grow Maine’s economy. And let’s face it, when you think of Maine as Vacationland, you don’t think of dirty, unhealthy air.”

Collins co-sponsored a bill this summer to postpone implementation of the new industrial boiler regulations, giving the EPA 15 months to review the issue and extending compliance deadlines from three years to five.

Pulp and paper industry officials in Maine have said the plants are crucial to their businesses and that the regulations are costly to comply with and overly strict. Opponents argue the delay will allow harmful toxins into the air.

Collins’ bipartisan legislation now has more than 40 co-sponsors and will give the EPA time to analyze the best ways to implement the standards, known as Boiler MACT rules, according to Kevin Kelley, a spokesman for Collins.

“Maine has lost more than a third of its manufacturing jobs during the past decade, and Sen. Collins remains committed to helping ensure that the Boiler MACT rules are crafted to protect public health without harming the forest products industry, which is the lifeblood of many small, rural communities,” Kelley said in a statement.